| 摘要 |
PURPOSE:To obtain a binder compsn. for a casting mold having extremely good warm strength and collapsing property by adding an ammonium phosphate compd. as a collapsing assistant to a melamine resin as a binder for a casting mold. CONSTITUTION:A binder compsn. for a casting mold consists essentially of a melamine resin and ammonium phosphate compd. The melamine resin refers to the melamine given with a methyrol group in the molecule by the reaction between melamine and formalin or the oligomer which is the initial condensation product and further the melamine resin mixed with a small amt. of other resin is also included. The ammonium phosphate compd. refers to, for example, ammonium primary phosphate, ammonium secondary phosphate, ammonium tertiary phosphate, ammonium polyphosphate, etc. |
